Minimal reproducible sample for Flutter WebView blurry/low-resolution rendering on Impeller OpenGLES (Android).
WebView renders blurry/low-resolution on devices with ARM Mali-G52 GPUs after Flutter 3.44.1. Setting EnableImpeller=false (Skia fallback) restores correct rendering.
Flutter uses the Impeller OpenGLES backend on this device (not Vulkan). Platform view uses SurfaceProducer with legacy composition strategy.
- Flutter 3.44.1 (
flutter --version) - Android device with ARM Mali-G52 GPU (e.g. Rockchip RK3576, Android 14)
- USB debugging enabled
1. Broken — Impeller enabled (default)
flutter run \
--flavor impellerOn \
--dart-define=IMPELLER_ENABLED=trueObserve: WebView content is blurry/low-resolution on physical screen.
2. Fixed — Impeller disabled (Skia fallback)
flutter run \
--flavor impellerOff \
--dart-define=IMPELLER_ENABLED=falseObserve: WebView renders correctly.
Impeller: ON
Impeller: OFF
Impeller: ON
Impeller: OFF
The two flavors control EnableImpeller via AndroidManifest.xml:
<!-- impellerOn/AndroidManifest.xml -->
<meta-data
android:name="io.flutter.embedding.android.EnableImpeller"
android:value="true" />
<!-- impellerOff/AndroidManifest.xml -->
<meta-data
android:name="io.flutter.embedding.android.EnableImpeller"
android:value="false"
tools:replace="android:value" />| Field | Value |
|---|---|
| GPU | ARM Mali-G52 (GLES: ARM, Mali-G52, OpenGL ES 3.2 v1.g15p0-01eac0) |
| SoC | Rockchip RK3576 |
| Android | 14 (API 34) |
| Impeller backend | OpenGLES |
| Platform view | SurfaceProducer + legacy composition |
Key lines captured via adb logcat on startup:
D libEGL : loaded /vendor/lib64/egl/libGLES_mali.so
I flutter : [IMPORTANT:flutter/shell/platform/android/android_context_gl_impeller.cc(104)] Using the Impeller rendering backend (OpenGLES).
I PlatformViewsChannel : Using legacy platform view rendering strategy.
I PlatformViewsController: Hosting view in view hierarchy for platform view: 0
I PlatformViewsController: PlatformView is using SurfaceProducer backend
Vulkan layers load (VK_LAYER_KHRONOS_validation found) but Flutter never initializes a Vulkan context — goes straight to OpenGLES.
[✓] Flutter (Channel stable, 3.44.1, on macOS 26.4.1 25E253 darwin-arm64, locale en-US)
• Flutter version 3.44.1 on channel stable at /Users/bart.vanhooft/.asdf/installs/flutter/3.44.1
• Upstream repository https://github.com/flutter/flutter.git
• Framework revision 924134a44c (5 days ago), 2026-05-29 12:13:22 -0400
• Engine revision c416acfeb8
• Dart version 3.12.1
• DevTools version 2.57.0
[✓] Android toolchain - develop for Android devices (Android SDK version 35.0.0)
• Android SDK at /Users/bart.vanhooft/Library/Android/sdk
• Platform android-36, build-tools 35.0.0
• Java binary at: /Applications/Android Studio.app/Contents/jbr/Contents/Home/bin/java
• Java version OpenJDK Runtime Environment (build 17.0.11+0-17.0.11b1207.24-11852314)
• All Android licenses accepted.
[✓] Connected device (3 available)
• Kindermann TD 12xx (mobile) • 10.50.0.103:46193 • android-arm64 • Android 14 (API 34)